排序方式: 共有47条查询结果,搜索用时 15 毫秒
41.
具有裂纹-碰摩耦合故障转子-轴承系统的动力学研究 总被引:9,自引:0,他引:9
以非线性动力学和转子动力学理论为基础,分析了带有碰摩和裂纹耦合故障的弹性转子系统的复杂运动,在考虑轴承油膜力的同时构造了含有裂纹和碰摩故障转子系统的动力学模型。针对短轴承油膜力和碰摩-裂纹转子系统的强非线性特点,采用Runge-Kutta法对该系统由碰摩和裂纹耦合故障导致的非线性动力学行为进行了数值仿真研究,发现该类碰摩转子系统在运行过程中存在周期运动、拟周期运动和混沌运动等丰富的非线性现象,该研究结果为转子-轴承系统故障诊断、动态设计和安全运行提供理论参考。 相似文献
42.
A new protocol for the synthesis of imides has been developed. In the presence of copper catalyst, N‐benzylamides were oxidized to the corresponding imides by TBHP/TEMPO system in moderate to good yields. 相似文献
43.
Ji L Rao M Zheng H Zhang L Li Y Duan W Guo J Cairns EJ Zhang Y 《Journal of the American Chemical Society》2011,133(46):18522-18525
The loss of sulfur cathode material as a result of polysulfide dissolution causes significant capacity fading in rechargeable lithium/sulfur cells. Here, we use a chemical approach to immobilize sulfur and lithium polysulfides via the reactive functional groups on graphene oxide. This approach enabled us to obtain a uniform and thin (around tens of nanometers) sulfur coating on graphene oxide sheets by a simple chemical reaction-deposition strategy and a subsequent low-temperature thermal treatment process. Strong interaction between graphene oxide and sulfur or polysulfides enabled us to demonstrate lithium/sulfur cells with a high reversible capacity of 950-1400 mA h g(-1), and stable cycling for more than 50 deep cycles at 0.1C (1C = 1675 mA g(-1)). 相似文献
44.
45.
46.
47.